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ARS Home » Midwest Area » Ames, Iowa » National Animal Disease Center » Ruminant Diseases and Immunology Research » Research » Publications at this Location » Publication #427786
Research Project: Host-pathogen Interactions and Control Strategies for Bacterial Respiratory Pathogens in Cattle

Location: Ruminant Diseases and Immunology Research

Title: Mycoplasma leachii strain PG50 shows reduced adherence and invasion compared to M. bovis strains 428E and PG45

Author
item Nielsen, Daniel
item Hau, Samantha
item Holthausen, David
item Dassanayake, Rohana
item Kaplan, Bryan

Submitted to: Veterinary Research Communications
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 9/5/2025
Publication Date: N/A
Citation: N/A

Interpretive Summary: Mycoplasma leachii has caused arthritis, mastitis, and abortion in dairy cattle in Australia, Argentina, and China. M. leachii is a member of the mycoides cluster. Some of the mycoides cluster bacteria cause foreign animal diseases with biosecurity concerns. We compared how well M. leachii adhered to and invaded three different cell types. We found that M. leachii adhered and invaded less efficiently than Mycoplasma bovis, which causes disease in cattle in the United States. We also found that bovine viral diarrhea virus (BVDV-1b) did not change the results. The length of time (2 or 24 hours) or cell type (epithelial or fibroblast) did not change the results. We should further study if M. leachii is representative of other bacteria in the mycoides cluster.

Technical Abstract: Mycoplasma leachii is a member of the “Mycoplasma mycoides cluster”, which includes both the causative agent of contagious bovine pleuropneumonia (Mycoplasma mycoides subsp. mycoides) and the causative agent of contagious caprine pleuropneumonia (Mycoplasma capricolum subsp. capripneumoniae). M. leachii has been associated with severe outbreaks of polyarthritis, mastitis, and abortion in dairy cattle in Australia, Argentina, and China. As M. leachii has both clinical, veterinary implications and is related to other foreign animal diseases of economic importance, we sought to investigate differences in adherence to and invasion of different bovine cells between M. leachii type strain PG50 and M. bovis strains (type strain PG45 and field strain 428E). Specifically, we tested the strains with Madin-Darby bovine kidney (MDBK), bovine turbinate (BTu), and the carticular progenitor 5 (CP5) cells. Additionally, we tested the MDBK and BTu cells with both non-cytopathic bovine viral diarrhea virus (BVDV-1b) positive and BVDV negative fetal bovine serum. M. leachii strain PG50 adhered and invaded less efficiently than M. bovis strains 428E and PG45 regardless of the incubation time (2 hours vs 24 hours), tested cells (MDBK, BTu, or CP5), cell type (epithelial or fibroblast), or presence of BVDV. Future work should further characterize M. leachii to further assess its risk to animal health and compare it phenotypically to other members of the M. mycoides cluster.